Transparent Microcomposite Films Based on a Ce-Doped Li₆Gd(BO₃)₃ Scintillator for Radiation Detection

Scintillators are widely used for high-energy radiation detection. Hybrid inorganic-organic composite scintillators with high light yields, high light decay rates, excellent stability, and low costs are in great demand. Here, we report a novel scintillator composed of Ce-doped Li₆Gd(BO₃)₃ (LGBO) microphosphors (MPs) and polymethyl methacrylate for X-ray and thermal neutron detection. The Ce-doped LGBO MPs, fabricated using a facile high-temperature solid-state reaction method, exhibit intense blue light at 416 nm under X-ray and UV excitation and have a high photoluminescence quantum yield of ∼63%. More importantly, the composite scintillator based on these MPs has excellent transparency and luminescence intensity. The luminescence integral intensity of composite scintillators is superior to that of commercial CsI:Na under X-ray excitation, and the light yield under thermal neutron irradiation is 21,000 photons/thermal neutron. The scintillation decay time is found to be below 600 ns. The neutron-gamma signal discrimination and neutron detection efficiency of the composite scintillators are acceptable for practical application. There is an excellent separation between neutron and background events. It represents significant improvements in scintillator performances, especially for reliable thermal neutron scintillators that are likely to improve the data qualities of scientific instruments, including charge-coupled device-based imagers and Anger logic-based position-sensitive detectors in neutron user facilities.